Post-translational modifications of alpha5beta1 integrin by glycosaminoglycan chains. The alpha5beta1 integrin is a facultative proteoglycan.
J Biol Chem
; 272(19): 12529-35, 1997 May 09.
Article
em En
| MEDLINE
| ID: mdl-9139704
Cell-fibronectin interactions, mediated through several different receptors, have been implicated in a wide variety of cellular properties. Among the cell surface receptors for fibronectin, integrins are the best characterized, particularly the prototype alpha5beta1 integrin. Using [125I]iodine cell surface labeling or metabolic radiolabeling with sodium [35S]sulfate, we identified alpha5beta1 integrin as the only sulfated integrin among beta1 integrin heterodimers expressed by the human melanoma cell line Mel-85. This facultative sulfation was confirmed not only by immunoprecipitation reactions using specific monoclonal antibodies but also by fibronectin affinity chromatography, two-dimensional electrophoresis, and chemical reduction. The covalent nature of alpha5beta1 integrin sulfation was evidenced by its resistance to treatments with high ionic, chaotrophic, and denaturing agents such as 4 M NaCl, 4 M MgCl2, 8 M urea, and 6 M guanidine HCl. Based on deglycosylation procedures as chemical beta-elimination, proteinase K digestion, and susceptibility to glycosaminoglycan lyases (chondroitinase ABC and heparitinases I and II), it was demonstrated that the alpha5beta1 heterodimer and alpha5 and beta1 integrin subunits were proteoglycans. The importance of alpha5beta1 sulfation was strengthened by the finding that this molecule is also sulfated in MG-63 (human osteosarcoma) and HCT-8 (human colon adenocarcinoma) cells.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Processamento de Proteína Pós-Traducional
/
Receptores de Fibronectina
/
Glicosaminoglicanos
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
1997
Tipo de documento:
Article
País de afiliação:
Brasil
País de publicação:
Estados Unidos